<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        body{
            background-color: #000;
        }
        ul {
            list-style: none;
            padding: 0;
            margin: 0;
        }

        .clearfix::after {
            content: "";
            display: block;
            clear: both;
        }

        ul {
            border: 1px solid red;
        }

        ul li {
            border: 5px solid #fff;
            width: 100px;
            height: 100px;
            float: left;
            margin-right: -40px;
            border-radius: 50%;
            overflow: hidden;
            transition: margin-right 0.5s
        }

        ul li img{
            width: 100px;
            height: 100px;
        }
        ul li:hover{
            margin-right: 0;
        }
    </style>
</head>

<body>
    <ul class="clearfix">
        <li><img src="./assets/head1.jpg" alt=""></li>
        <li><img src="./assets/head2.jpg" alt=""></li>
        <li><img src="./assets/head3.jpg" alt=""></li>
        <li><img src="./assets/head4.jpg" alt=""></li>
    </ul>
</body>

</html>